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Description:This 1981 photograph depicted a number of Coplin jars ready for what would be a trichrome staining procedure.

Trichrome Staining Procedure

The trichrome stain is a simple and stable stain to use that renders organisms easier to detect because the nuclear chromatin and cytoplasm stain different colors, unlike iron hematoxylin which is a monochromatic stain. Staining containers such as Coplin jars arranged in a row make staining 1" × 3" slides systematic and simple when moving from one solution to another. Besides our example of trichrome staining of PVA-fixed specimens, one should also be aware that there are many other fixatives and staining procedures available.

The specimens usually consist of fresh stool or stool fixed in polyvinyl alcohol (PVA) smeared on microscope slides and allowed to air dry or dry on a slide warmer at 60°C. Stool preserved in sodium acetate-acetic acid-formalin (SAF) or some of the one-vial fixatives can also be used.


There are seven steps to this procedure, requiring the following solutions:

1.- 70% Ethanol plus iodine: prepare a stock solution by adding iodine crystals to 70% alcohol until you obtain a dark solution. To use, dilute the stock with 70% alcohol until a dark reddish brown color or strong tea color is obtained

2.- 70% Ethanol (twice)

3.- Trichrome Stain: may be purchased commercially

4.- 90% Acid Ethanol

    - 90% ethanol = 99.5 ml

    - Acetic acid (glacial) = 0.5 ml

5.- 95% ethanol

6.- 100% ethanol (twice)

7.- Xylene or xylene substitute (twice)

High Resolution: Click here for hi-resolution image (4.5 MB)
Content Providers(s):CDC/ Dr. Mae Melvin
Creation Date:1981
Photo Credit:
Links:CDC - Div. of Parasitic Diseases, DPDx; Selection of Standard Techniques for Examination of Fecal Specimens
CDC – Div. of Parasitic Diseases, DPDx; Stool Specimens: Staining Procedures
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Copyright Restrictions:None - This image is in the public domain and thus free of any copyright restrictions. As a matter of courtesy we request that the content provider be credited and notified in any public or private usage of this image.